Today's reality includes emergence and spread of multi-drug resistant organisms and new infectious agents, a growing concern for worldwide pandemics, the use of infectious agents in offensive bio-warfare, an enlarging list of opportunistic infections seen in immune compromised patients and the continued global death and suffering due to HIV and tuberculosis. These challenges to human health necessitate comprehensive interdisciplinary training programs for the next generation of scientists in studies of the microbe-host interface. This new training program includes faculty from 7 departments (4 basic sciences and 3 clinical) and 3 PhD, MD, MD/PhD, and DVM degree granting programs. The hub for the program will be the Center for Microbial Interface Biology (CMIB), a Center focused on Infectious Diseases Research and Biodefense. The PI is a physician scientist who serves as Director of the CMIB and the Division of Infectious Diseases. The Co-PI is a PhD scientist with a strong research program and career fostered by academic health centers. Thus the PI and co-PI represent an outstanding collaborative team to oversee this broad innovative program which emphasizes: 1) a highly interactive scientific community, 2) a multidisciplinary approach to science, 3) exposure of trainees to the biomedical research community of a large academic health sciences center, 4) integration of the clinical and basic sciences, and 5) exposure to experienced and talented PhD, MD, MD/PhD and DVM/PhD scientist educators and mentors. The major thematic areas are 1) The microbial response to infection and 2) The host response to infection (innate, acquired, respiratory biology). The program describes an Oversight and Selection Committee, an outstanding External Advisory Committee and the necessary administrative structure to execute the program. Emphasis is placed on recruitment of individuals from under represented racial/ethnic groups and on formal instruction for the responsible conduct of research. We request 2 predoctoral and 2 postdoctoral slots/year. We believe that the curriculum, faculty, resources, and institutional support will make this program attractive to outstanding students who will receive a unique multidisciplinary training experience focused on the microbe-host interface.